Doesn’t lock in - Pro Mag AR15/M16 Low Receiver Magazine Vise Block

Like a previous review my mag block also wouldn’t lock into place when the block was inserted into mag well when the stopper was level to the bottom of the mag well. In all three other positions it does lock into the mag well but my lower won’t rest level on the blocks stopper. It looks like the slot was milled or molded a little too high on the one side only.